Faculty Bibliography

Latent class models are widely used to identify unobserved subgroups (i.e., latent classes) based upon one or more manifest variables. The probability of belonging to each subgroup is typically modeled as a function of a set of measured covariates. In this paper, we extend existing latent class models to incorporate matrix covariates. This research is motivated by a randomized placebo-controlled depression clinical trial. One study goal is to identify a subgroup of subjects who experience symptoms improvement early on during antidepressant treatment, which is considered to be an indication of a placebo rather than a true pharmacological response. We want to relate the likelihood of belonging to this subgroup of early responders to baseline electroencephalography (EEG) measurement that takes the form of a matrix. The proposed method is built upon a low rank Candecomp/Parafac (CP) decomposition of the target coefficient matrix through low-dimensional latent variables, which effectively reduces the model dimensionality. We adopt a Bayesian hierarchical modeling approach to estimate the latent variables, which allows a flexible way to incorporate prior knowledge about covariate effect heterogeneity and offers a data-driven method of regularization. Simulation studies suggest that the proposed method is robust against potentially misspecified rank in the CP decomposition. With the motivating example we show how the proposed method can be applied to extract valuable information from baseline EEG measurements that explains the likelihood of belonging to the early responder subgroup, helping to identify placebo responders and suggesting new targets for the study of placebo response.

BACKGROUND: Moderators of differential psychotherapy outcome for posttraumatic stress disorder (PTSD) are rare, yet have crucial clinical importance. We tested the moderating effects of trauma type for three psychotherapies in 110 unmedicated patients with chronic DSM-IV PTSD. METHODS: Patients were randomized to 14 weeks of prolonged exposure (PE, N = 38), interpersonal psychotherapy (IPT, N = 40), or relaxation therapy (RT, N = 32). The Clinician-Administered PTSD Scale (CAPS) was the primary outcome measure. Moderator candidates were trauma type: interpersonal, sexual, physical. We fit a regression model for week 14 CAPS as a function of treatment (a three-level factor), an indicator of trauma type presence/absence, and their interactions, controlling for baseline CAPS, and evaluated potential confounds. RESULTS: Thirty-nine (35%) patients reported sexual, 68 (62%) physical, and 102 (93%) interpersonal trauma. Baseline CAPS scores did not differ by presence/absence of trauma types. Sexual trauma as PTSD criterion A significantly moderated treatment effect: whereas all therapies had similar efficacy among nonsexually-traumatized patients, IPT had greater efficacy among sexually traumatized patients (efficacy difference with and without sexual trauma: IPT vs. PE and IPT vs. RT P's < .05), specifically in PTSD symptom clusters B and D (P's < .05). CONCLUSIONS: Few studies have assessed effects of varying trauma types on effects of differing psychotherapies. In this exploratory study, sexual trauma moderated PTSD outcomes of three therapies: IPT showed greater benefit for sexually traumatized patients than PE or RT. The IPT focuses on affect to help patients determine trust in their current environments may particularly benefit patients who have suffered sexual assault.

PURPOSE/BACKGROUND: Deficits in N-methyl-D-aspartate receptor (NMDAR) function contribute to symptoms and cognitive dysfunction in schizophrenia and are associated with impaired generation of event-related potential measures including auditory mismatch negativity. Parallel studies of the NMDAR agonist d-serine have suggested that sensitivity of these measures to glutamate-based interventions is related to symptomatic and cognitive response. Bitopertin is a selective inhibitor of glycine transport. This study investigates effects of bitopertin on NMDAR-related event-related potential deficits in schizophrenia. METHODS/PROCEDURES: Patients with schizophrenia/schizoaffective disorder were treated with bitopertin (10 mg, n = 29), in a double-blind, parallel group investigation. Auditory mismatch negativity served as primary outcome measures. Secondary measures included clinical symptoms and neurocognitive performance. FINDINGS/RESULTS: No significant changes were seen with bitopertin for neurophysiological, clinical, or neurocognitive assessments. IMPLICATIONS/CONCLUSIONS: These findings represent the first assessment of the effect of bitopertin on neurophysiological biomarkers. Bitopertin did not significantly affect either symptoms or NMDAR-related biomarkers at the dose tested (10 mg). Mismatch negativity showed high test-retest reliability, supporting its use as a target engagement measure.

Antidepressant medications are commonly used to treat depression, but only about 30% of patients reach remission with any single first-step antidepressant. If the first-step treatment fails, response and remission rates at subsequent steps are even more limited. The literature on biomarkers for treatment response is largely based on secondary analyses of studies designed to answer primary questions of efficacy, rather than on a planned systematic evaluation of biomarkers for treatment decision. The lack of evidence-based knowledge to guide treatment decisions for patients with depression has lead to the recognition that specially designed studies with the primary objective being to discover biosignatures for optimizing treatment decisions are necessary. Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care (EMBARC) is one such discovery study. Stage 1 of EMBARC is a randomized placebo controlled clinical trial of 8 week duration. A wide array of patient characteristics is collected at baseline, including assessments of brain structure, function and connectivity along with electrophysiological, biological, behavioral and clinical features. This paper reports on the data analytic strategy for discovering biosignatures for treatment response based on Stage 1 of EMBARC.

Perceived social support (PSS) has been related to physical and mental well-being in typically developing individuals, but systematic characterizations of PSS in autism spectrum disorder (ASD) are limited. We compared self-report ratings of the multidimensional scale of PSS (MSPSS) among age- and IQ-matched groups of adults (18-58 years) with cognitively high-functioning ASD (N = 41), or attention-deficit/hyperactivity disorder (ADHD; N = 69), and neurotypical controls (NC; N = 69). Accompanying group comparisons, we used machine learning random forest (RF) analyses to explore predictors among a range of psychopathological and socio-emotional variables. Relative to both ADHD and NC, adults with ASD showed lower MSPSS ratings, specifically for the friends subscale (MSPSS-f). Across ASD and ADHD, interindividual differences in autism severity, affective empathy, symptoms of anxiety related to social interactions, hyperactivity/impulsivity, and somatization best predicted MSPSS-f. These relationships did not differ between clinical groups. While group comparisons demonstrated greater impairment in individuals with ASD, analyzing individuals' characteristics revealed cross-diagnoses similarities in regard to their MSPSS-f relationships. This is consistent with the Research Domain Criteria framework, supporting a trans-diagnostic approach as on the path toward "precision medicine." Autism Res 2017. (c) 2017 International Society for Autism Research, Wiley Periodicals, Inc.

In a randomized clinical trial (RCT), it is often of interest not only to estimate the effect of various treatments on the outcome, but also to determine whether any patient characteristic has a different relationship with the outcome, depending on treatment. In regression models for the outcome, if there is a non-zero interaction between treatment and a predictor, that predictor is called an "effect modifier". Identification of such effect modifiers is crucial as we move towards precision medicine, that is, optimizing individual treatment assignment based on patient measurements assessed when presenting for treatment. In most settings, there will be several baseline predictor variables that could potentially modify the treatment effects. This article proposes optimal methods of constructing a composite variable (defined as a linear combination of pre-treatment patient characteristics) in order to generate an effect modifier in an RCT setting. Several criteria are considered for generating effect modifiers and their performance is studied via simulations. An example from a RCT is provided for illustration.

Importance: Low-income minority children living in urban neighborhoods are at high risk for mental health problems and underachievement. ParentCorps, a family-centered, school-based intervention in prekindergarten, improves parenting and school readiness (ie, self-regulation and preacademic skills) in 2 randomized clinical trials. The longer-term effect on child mental health and academic performance is not known. Objective: To examine whether ParentCorps delivered as an enhancement to prekindergarten programs in high-poverty urban schools leads to fewer mental health problems and increased academic performance in the early elementary school years. Design, Setting, and Participants: This is a 3-year follow-up study of a cluster randomized clinical trial of ParentCorps in public schools with prekindergarten programs in New York City. Ten elementary schools serving a primarily low-income, black student population were randomized in 2005, and 4 consecutive cohorts of prekindergarten students were enrolled from September 12, 2005, through December 31, 2008. We report follow-up for the 3 cohorts enrolled after the initial year of implementation. Data analysis was performed from September 1, 2014, to December 31, 2015. Interventions: ParentCorps included professional development for prekindergarten and kindergarten teachers and a program for parents and prekindergarten students (13 two-hour group sessions delivered after school by teachers and mental health professionals). Main Outcomes and Measures: Annual teacher ratings of mental health problems and academic performance and standardized tests of academic achievement in kindergarten and second grade by testers masked to the intervention or control group randomization. Results: A total of 1050 children (4 years old; 518 boys [49.3%] and 532 girls [50.7%]) in 99 prekindergarten classrooms participated in the trial (88.1% of the prekindergarten population), with 792 students enrolled from 2006 to 2008. Most families in the follow-up study (421 [69.6%]) were low income; 680 (85.9%) identified as non-Latino black, 78 (9.8%) as Latino, and 34 (4.3%) as other. Relative to their peers in prekindergarten programs, children in ParentCorps-enhanced prekindergarten programs had lower levels of mental health problems (Cohen d = 0.44; 95% CI, 0.08-0.81) and higher teacher-rated academic performance (Cohen d = 0.21; 95% CI, 0.02-0.39) in second grade. Conclusions and Relevance: Intervention in prekindergarten led to better mental health and academic performance 3 years later. Family-centered early intervention has the potential to prevent problems and reduce disparities for low-income minority children. Trial Registration: clinicaltrials.gov Identifier: NCT01670227.

BACKGROUND: Social anxiety disorder (SAD) typically onsets in adolescence and is associated with multiple impairments. Despite promising clinical interventions, most socially anxious adolescents remain untreated. To address this clinical neglect, we developed a school-based, 12-week group intervention for youth with SAD, Skills for Academic and Social Success (SASS). When implemented by psychologists, SASS has been found effective. To promote dissemination and optimize treatment access, we tested whether school counselors could be effective treatment providers. METHOD: We randomized 138, ninth through 11th graders with SAD to one of three conditions: (a) SASS delivered by school counselors (C-SASS), (b) SASS delivered by psychologists (P-SASS), or (c) a control condition, Skills for Life (SFL), a nonspecific counseling program. Blind, independent, evaluations were conducted with parents and adolescents at baseline, post-intervention, and 5 months beyond treatment completion. We hypothesized that C-SASS and P-SASS would be superior to the control, immediately after treatment and at follow-up. No prediction was made about the relative efficacy of C-SASS and P-SASS. RESULTS: Compared to controls, adolescents treated with C-SASS or P-SASS experienced significantly greater improvement and reductions of anxiety at the end of treatment and follow-up. There were no significant differences between SASS delivered by school counselors and psychologists. CONCLUSION: With training, school counselors are effective treatment providers to adolescents with social anxiety, yielding benefits comparable to those obtained by specialized psychologists. Questions remain regarding means to maintain counselors' practice standards without external support.

Although disrupted function of frontal and limbic areas of cerebral cortex are closely associated with major depressive disorder (MDD) and schizophrenia (SZ), cellular pathology has also been found in other brain areas, including primary sensory areas. Auditory cortex is of particular interest, given the prominence of auditory hallucinations in SZ, and sensory deficits in MDD. We used stereological sampling methods in auditory cortex to look for cellular differences between MDD, SZ and non-psychiatric subjects. Additionally, as all of our MDD subjects died of suicide, we evaluated the association of suicide with our measurements by selecting a SZ sample that was divided between suicide and non-suicide subjects. Measurements were done in primary auditory cortex (area A1) and auditory association cortex (area Tpt), two areas with distinct roles in sensory processing and obvious differences in neuron density and size. In MDD, densities of GABAergic interneurons immunolabeled for calretinin (CR) and calbindin (CB) were 23-29% lower than non-psychiatric controls in both areas. Parvalbumin (PV) interneurons (counted only in area Tpt) showed a nominally smaller (16%) reduction that was not statistically significant. Total neuron and glia densities measured in Nissl stained sections did not show corresponding reductions. Analysis of suicide in the SZ sample indicated that reduced CR cell density was associated with suicide, whereas the densities of CB and other cells were not. Our results are consistent with previous studies in MDD that found altered GABA-associated markers throughout the cerebral cortex including primary sensory areas.

Objectives: Organizational Skills Training (OST), is a 10-week psychosocial intervention found effective in improving organizational, time management, and planning (OTMP) skills in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Little is known about the feasibility of identifying brain markers for treatment response. Using resting state fMRI (R-fMRI), we aimed to examine neuronal correlates of post-treatment change as a first step toward larger controlled studies of objective predictors of treatment response. Methods: We examined pre- and post-OST R-fMRI data of 15 children (12 males; mean age: 9+/-1 year) with ADHD and significant impairments in OTMP skills indexed by total scores on Children's Organizational Skills Scales-Parent (COSS-P) or Teacher (COSS-T). Our primary outcome measure was the change in COSS-P scores. As secondary summary outcome measure, we used prepost Z-score differences averaged across COSS-T, Homework Problems Checklist, Academic Progress Report and Academic Performance Rating scales. We selected a priori the intrinsic functional connectivity (iFC) of the dorsal anterior cingulate cortex (dACC), based on its role on cognitive control. Multivariate distance matrix regression (MDMR) analysis additionally allowed for whole-brain explorations. Follow-up iFC analyses were conducted on regions with significant within-subject post-OST differences by MDMR analysis. Results: COSS-P decreased significantly (t=7.1, p< 0.0001). In a cluster involving striatum bilaterally, dACC iFC decreased post-OST; these decreases were positively correlated with COSS-P improvements (r=.34, NS) and to improvements in the summary outcome (r=.63; p<0.03). MDMR analyses revealed iFC changes in the right medial and lateral precentral cortex. Followup seed-based iFC analyses of this region showed significant decreases in cortico-striatal iFC post-OST. Conclusions: Results support the feasibility of identifying changes in brain iFC after OST. Two distinct analysis converged on decreased corticosubcortical iFC post-treatment which related to change in clinical measures. As decreases in striato-cortical iFC characterize typical development, results suggest regionally-specific enhanced maturational effects of OST